ML20031A026
| ML20031A026 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek, Callaway  |
| Issue date: | 09/14/1981 |
| From: | Petrick N STANDARDIZED NUCLEAR UNIT POWER PLANT SYSTEM |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| SLNRC-81-101, NUDOCS 8109180305 | |
| Download: ML20031A026 (20) | |
Text
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SNUPPS Standardded Nuclear Urut Power Ptint System 5 Choke Cherry Road Nicholas A. Petrick Ro vil land 208E3 Exocutive Director September 14, 1981 SLNRC 81-1 01 FILE: 0541 SUBJ: RSB Review
/.
A-h.W t /(N-t/Mr. Harold R. Denton, Director g
j Office of Nuclear Reactor Regulation v
N
\\
U.S. Nuclear Regulatory Comission D
h Washington, D. C.
20555 6*
A
,N Docket Nos. STN 50-482, STii 50-483, and STN 50-486 s 2
(
Ref:
1.
SLNRC 81-83, dated September 1,1981, same sub h,
[N 2.
SLNRC 81-96, dated September 9,1981, same subje Qbg Oear Mr. Denton:
The referenced letters provided additional information for the NRC's Reactor System Branch in order to complete their review of the SNUPPS FSAR. Two additional matters require added information and are dis-cussed below.
Agenda item #5 of the July 21, 1981 meeting concerned Refueling Water Storage Tank sizing and setpoints. Enclosure A to this letter is FSAR changes that provide the required inforn stion and will be incorporated in the next revision to the SNUPPS FSAR.
l Agenda item #15-10, which was discussed in the August 12, 1981 meeting, concerned protection afforded the centrifugal charging pumps in a situa-tion where they could be running against a shutoff head pressure. Safety-relatea instrumentation and controls will be added to the SNUPPS design to protect the centrifugal charging pumps when subjected to these condi-tions. The additional instrumentation and associated control will reopen motor-operated valves HV-110 and HV-lll in the miniflow lines when the pumps' flow rate approaches minimum flow tonditions. The valves will re-close when the miniflow line function is no longer required. Details of this design change will be provided in the FSAR when engineering is more complete. This information should be available later in 1981, but will be provided at'least four months prior to fuel load of the first SNUPPS plan:..
This design change concept was discussed with the NRC on August 12 and it is felt that the above information should provide the hnC with sufficient l
QOOI s
Ifl 8109180305 810914' DR ADOCK 05000482 PDR
SLNRC 81-101 6
information to resolve the issue for the Callaway SER. Confirmation and -
final NRC acceptance of the design change could then be given after eng-neering detail is available.
Very' truly yours, Q,
i Nicholas A. Petrick RLS/jdk Enclosure cc:
J. K. Bryan UC G. L. Koester KGE D. T. McPhee KCFL D. F. Schnell UE W. A. Hansen NRC/ CAL T. E. Vandel NRC/WC I
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SNUPPS On coincidence of two-out-of-four low level signals from the RWST level transmitters, the emergency core cooling system (ECCS) pumps switch suction to the containment recirculation sump, as described in Section 6.3.2.
The low level setpoint indicates that (LS,ioo usable gallons remain in the RWST.
l Switchover for the spray pum;r, is manually initiated when the low-low level in the RWST is reached.
The low-low level indicates imminent depletian of the RWST.
Switchover ini-tiated at the time of the low-low level alarm ensures that the system piping remains full of water and that adequate NPSH for the spray pumps is maintained.
The RWST low-low level alarms and level indicators inform the operator of the need to make this switchover.
4 The time length of the ccntainment spray injection phase
.s given in Table 6.2.2-4.
These times are based on the minimum RWST volume and are given for credible combinations of minimum and maximum containment spray and ECCS operation and runout flow rates of these pumps.
The containment spray additive design flow rate is given in Table 0.5-2.
RECIRCULATION PHASE - The recirculation phase initiated by the operator manually shifting containment spray pump suction from the RWST to the containment recirculation sump.
The accident chronology for the containment spray system for the recirculation phase is provided in Table 6.2.2-3.
l V
.4 s LotA The RWST suction line valves remain open during the switchover to the recirculation phase to preclude the loss of supply to the containment spray pumps in the highly unlikely event that the isolation valve in the recirculation line is delayed in opening.
The operator then remote manually closes the motor-operated valves in the RWST suction lines.
If the predetermined amount of spray cdditiv6 defined in Section 6.5.2 has been added, a permissive signal from the spray additive tank level switches allows the operator to remote manually close the motor-operated valves in the spray additive supply lines to the containment spray additive eductor.
If l
this minimum level in the spray additive tank has not been reached, the valves cannot be manually closed.
[
The suction line from the containment recirculatien sump to the spray pump is a sloped line which precludes air from entering the system.
The single valve in the containment sump recirculation line for the containment spray pump is encapsulated and located outside the containment.
The flow l
paths from the spray pumps are the same as in the injection phase.
Check valves are provided in the recirculation sump suction lines to prevent the establishment of a flow path between the RWST and the containment sump.
i 6.2.2-7
SNUPPS SAFETY EVALUATION FOUR - The CSS is initially cested with the program given in Chapter 14.0.
Functional testing is done in accordance with Section 6.2.2.1.4.
Section 6.6 provides the ASME Boiler and Pressure Vessel Code,Section XI requirements that are appropriate for the CSS.
SAFETY EVALUATION FIVE - Section 3.2 delin'eates the quality group classification and seismic category applicable to the safety-related portion of this system and supporting systems.
Section 6.2.2.1.2.2 shows that safety-related compcaents meet the design and fabrication codes given in Section 3.2.
All the power supplies and the control functions necessary for the safe function of the CSS are Class IE, as described in Chapters 7.0 and 8.0.
SAFETY EVALUATION SIX - Section 6.2.2.1.2.1 describes pro-visions made to identify and isolate leakage or malfunction and to isolate the nonsafety-related portions of the system.
SAFETY EVALUATION SEVEN - Sections 6.2.4 and 6.2.6 provide the safety evaluation for the system containment isolation arrange-ment and testability.
SAFETY EVALUATION EIGHT - As shown by the containment analysis and the description of the analytical methods and models given in Section 6.2.1, the containment spray system, in conjunction with the emergency core cooling system and the containment fan coolers, is capable of removing sufficient heat energy and subsequent decay heat from the containment atmosphere fol-lowing the hypothesized LOCA and MSLE inside the containmpnt to maintain the containment pressure below the design pres-Curves showing sump temperature, heat generation rates, sure.
heat removal rates of the containment heat removal systems, and containment total pressure, vapor pressure, and tempera-ture as a function of time for minimum engineered safety features performance are also given in Section 6.2.1.
During the injection phase, all pressure transient analyses take credit for a spray system capable of delivering borated 100 F spray water at the design flow rate.
For the design basis LOCA and,MSLB accident, credit is taken for spray flow initiation within 60 seconds.
A minimum storage volure of 318,too usable gallons is avail-l able in the RWST to ensure that, after a LOCA, sufficient water is injected for emergency core cooling and for rapidly reducing the containment pressure and temperature.
In addi-tion, this minimum volume ensures that sufficient water is available in the containment sump to permit recirculation i
(
6.2.2-9
SNUPPS TABLE 6.2.2-3 (Sheet 2)
Recirculation Phase Time (Min)
Action 0.0 Reach Lo-L.-Z. level in RWST.
0.5 Manually initiate opening the containment sump recirculation valves (opening time max 30 sec).
1.0 Verify sump recirculation valves are open.
1.5 Manually initiate closing of RWST isolation valves.
If low level in the NaOH tank has been reached, manually initiate closing of NaOH tank outlet iso-lation valves.
If low level in the NaOH tank has not been reached, raanually initiate clos-ing of the above valves upon that level being reached.
The time that L -L.-L level in the RWST is reached following the event depends on whether full or partial ECCS and con-tainment spray flow is attained, and can be between I7A~and 515 minutes.
ECCS switchover occurs prior to reaching L.-L6 1 level.
i l
l 1
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TABLE 6.2.2-4 SPRAY INJECTION PilASE DURATION Operator Action Time Length of Case F1,w Condition ~
Single Failure for Spray Switchever Injection (min.)
Remarks i
1.
2 trains ECCS hone 30 seconds after receipt 26.4 Refer to Table 6.3r11.
2 trains of Spray of the low-low 2 alarm i
2.
2 trains ECCS RHR/RWST 30 seconds after the 19.T Refer to Table 6.3712, 2 trains Spray Valve fails to end of step 5 of ECCS T
25,400 gallons remain in close swited.over RWST above the empty alarm.
This remaining volume would provide an additional 2 minutes for operator action prior to receipt of the RWST 4
empty alarm.. (Based on an outflow of 17.680 gpm from 4
the conpletion of ECCS switchover until the empty i
a arm.)
~
3.
2 trains ECCS One Spray train 30 seconds after receipt 43.7 i
i train Spray fails of the low-low 2 alarm 4
2 trains Spray One train of 30 seconds after receipt 53.2 ECCS one train flow rates 1 train ECCS ECCS pumps as-of the low-low 2 alarm are as follows:
sumed to fail RHR 5100 gpm S1 660 gpm l
CC 550 gpm l
5 2 trains Spray CTMT Spray sump 30 seconds after receipt 26.4 Operator shuts down one l
2 trains ECCS valve fails to of the low-low 2 alarm spray train to protect the open pumpa 9
i L
4 4
SNUPPE TABLE 6.2.2-6 WATER SOURCES AND WATER LOSSES WHICH CONTRIBUTE TO THE WATER LEVEL WITHIN THE REACTOR BUILDING Water Sources Reactor coolant inventory 504,640 Lbm Accumulator tanks inventory 210,300 Lbm RWST minimum volume, @ 100 F 3, too, Elo Lbm Initial atmospher' water vapor 3,700 Lbm Containment spray additive solution 28,814 Lbm Total 3,997,664 Lbr Weight of Vapor Water Losses Water vapor at the time of containmGnt spray recirculation 120,200 Lbm Total Water in Liquid State Volume of water, liquid, @ 212 F 61,750 ft3 Volume of Liquid Water Losses 3
Incore instrumentation tunnel 9,100 ft 3
Reactor cavity (includes RCS volume) 10,500 ft Incore instrumentation tunnel sump 100 ft3 3
Containment recirculation sumps 1,000 ft Containment normal sumps 150 ft3 Refueling pool and upending pit 500 ft3 Miscellaneous wetted surfaces 1,200 fta 3
Total 22,550 ft SU-f t r Area Available for Buildup 2
@ El 2,000 ft 7,000 ft 2
@ El 2,001 ft-4 in.
11,750 ft Results E:.evation of water @ initiation I,602 ft - 4 in.
of ECCS switchover Elevation of water @ containment 2,003 ft - 10 in.
spray switchover
)
SNUPPS 1
Accumulator pressure is provided by a supply of nitrogen gas, and can be adjusted, as required, during normal plant opera-tion.
However, the accumulators are normally isolated from this nitrogen supply.
Gas relief valve.t on the accumulators protect them from pressures in excess of design pressure.
Accuraulator gas pressure is monitored by indicators and alarms.
Solenoid-operated vent valves are provided to depressurize the l
accumulators during emergency cold shutdown conditions.
The accumulators are located within the containment but out-side of the secondary shield wall which protects the tanks from missiles generated from a postulated LOCA.
Refueling Water Storage Tank The borated refueling water storage facility consists of a large outside storage tank (i.e., RWST) witL connections for borated demineralized water delivery to and receipt from the fuel pool cooling and cleanup system, the chemical and volume control system, the containment spray system, and the ECCS.
The RWST is a passive seismic Category I component and is re-quired only during the short term following a LOCA, MSLB, or any other accident requiring ECCS.
Therefore, neither redundancy nor tornado n._
sile protection is required.
The safety-related level instrumentation and the temperature monitoring instrumenta-tion associated with the RWST are designed with redundancy.
The RWST is vented directly to the atmosphere.
Tank overflow is directed to the waste holdup tank in the liquid radwaste system via the floor and equipment drain system.
Sample.
connections are also provided to allow periodic analysh, of the RWST contents.
An automatic heater system is provided to prevent the contents of the RWST from freezing.
The heater system consists of steam coils wrapped around the outside of the RWST, insulation on the RWST, electrical heat tracing on the exposed nonessential piping, and a heated enclosure for the essential piping, valves, and instrumentation.
These steam coils are serviced by the auxiliary steam system.
For freeze protection during colder periods of the year, the RWST is automatically main-tained above 50 F by using a temperature control valve to control steam flow to the steam coil heaters.
Redundant temperature instrumentation is provided to inform the operator of any degradation of the heating capability for the RWST.
Since the RWST is not normally used as a source of water hj during power operation, the tank level is administratively maintained.
The water level is maintained above the minimum level consistent with the 250,000 gallons required for injec-tion, transfer allowances, and instrument error allowances.
The RWST levels and volumes shown on Figure 6.3-7 are based on the following considerations.
Rev. 7 6.3-5 9/81
SNUPPS RM$7 l
V Injection Mode Allowance The injection mode of ECCS operation consists of the ECCS pumps (charging pumps, safety injection pumps, and residual heat removal pumps) and the containment spray pumps taking suction from the RWST and delivering to the reactor coolant system (RCS) and containment, respectively.
The RWST volume available for ECCS pump injection mode operation is 250,000 gallons.
Containment and RCS pressures are conservatively assumed to be O psig to maximize flow out of the RWST.
Flow out of the RWST during the injection mode includes con-servative allowances for two pumps of each type operating at the following flow rates:
Safety injection pump 450 gpm per pump Charging pump 450 gpm per pump kHR pump 4,500 gpm per pump Spray pump 3,7ts gpm per pump Total RWST outflow rate during injection mode operation is is,L50 gpm.
Based on the above minimum available RWST volume for injection mode operation and the maximum total flow rate out of the RWST, the shortest injection mode operation time is approximately 13 7 minutes.
Transfer Allowance - RHR, Charging, SI During the injection mode of ECCS operation, the operator
Upon receipt of the RHR auto switchover alarm (Lo-Lo-1), the operator is required to initiate the manual operations required to complete switchover in a timely manner.
The ECCS switchover from injection to cold leg recirculation is initiated automatically upon receipt of the RHR auto switchover trip signal and is completed via timely operator action at tha main control board.
Switchover is initiated via automatic opening of the containment recirculation sump isolation valves (5811 A/B).
This automatic action aligns the suction of the RER pumps to the containment recirculation sump to ensure continued availability of a suction source.
Manual actions 1 through 5 of Table 6.3-8 must be performed following switchover
~ initiation prior to loss of the RWST transfer allowance to ensure that all ECCS pumps are protected with suction flow available from the containment sump.
The ECCS switchover pro-cedure is structured so that the operator simultaneously switches both trains of the ECCS from injection to recircula-tion, repositioning functionally similar switches as part of the same procedural steps.
Rev. 7 6.3-5a 9/81
N SNUPPS Iv The time available for switchover is dependent on the flow rate out of the RWST as the switchover manual actions are performed.
As ECCS valves are reposit ioned, the flow rate out of the RWST is reduced in magnitude.
In order to analyze the time available for switchover, the following conservative bases are established:
1.
The RWST transfer allowance available for ECCS pump switchover is 100,000 gallons.
2.
Containment and RCS pressures for large break conditions are conservatively assumed to be O psig.
Thus, no credit is taken for the reduction in RWST outflow that will result with higher ccntainment and RCS pressures fol-lowing a large break.
Based on the above criteria, the flow rates out of the RWST as a function of switchover manual action are itemized in Table 6.3-11 for large breaks.
The large break with single failure constitutes the condition where RWST outflow is the greatest.
Dperator action times assumed per switchover step and change in RWST volume per switchover step for this condition are itemized in Table 6.3-12.
Flow rate data for small breaks are less than for large breaks and are not included in Table 6.3-12.
The flow rate out of the RWST for the large LOCA with the single failure of the RHR/RWST isolation valve (8812 A or B) to close requires 6o,33o gallons for performing ECCS switch-over manual actions.
This volume is less than the transfer allowance of 100,000 gallons, which ensures that the switchover steps necessary to protect all ECCS pumps can be accomplished before the transfer allowance is depleted.
Transfer Allowance - Containment Spray The RWST volume between the Lo-Lo-2 setpoint and the empty setpoint is required for containment spray pump switchover from the RWST to the sump.
The available volume in 15,650 gallons.
With both spray pumps operating, this volume pro-vides a minimum switchover time of 2.1 minutes.
This switch-over time is consistent with the operator action time of 1.75 minutes provided in Table 6.2.2-3.
As shown on Figure 6.3-7, the total transfer allowance for ECCS and containment spray pump switchover is 115,650 gallons.
In the worst single failure case, the total outflow from the RWST during ECCS pump switchover is 63,33o ga? lons, leaving 47,3Eo gallons for containment spray pump switencver.
At the completion of the switchover steps listed in Table 6.3-12, i t, 4%o gpm is being drawn from the RWST by two containment spray pumps, and the RHR pump and sump line are still lined up to the RWST due to failure of HV 8812A or B to close.
Rev. 7 6.3-5b 9/81
SNUPPS 1
y Failure of HV 8812A or B to close will be mitigated by operator action to immediately proceed with containment spray pump switchover at the completion of step 5 on Table 6.3-12 rather than waiting for the Lo-Lo-2 alarm.
HV 8812A/B position lights will indicate if the valve is not fully closed and also indicate loss of control or motive power to the valve by being unlit.
The time required to complete containment spray pump switchover is 1.75 minutes.
This will draw another ZE,19e gallons from i
the RWST at a flow rate of 12,690 gpm, Since the available transfer allowance is 47,3Ee gallons, the containment spray pumps can be switched over prior to depletion of the RWST.
Instrument Error The level measurement system for the RWCT includes four level transmitters, each of which have five setpoints, High, Low, Lo-Lo-1, Lo-Lo-2, and Empty.
Two out of four level transmitters sensing an individual setpoint will initiate the appropriate alarm or automatic action.
If any ringle transmitter's setpoint drifts high or low at one tank level, its setpoint at all other levels will drift in the sane direction.
Therefore, all available RWST volumes are verified under two separate cases, all setpoints drifting high and all setpoints drifting low.
This results in a 1.35 foot plus raargin on the Low setpoint and a 1.35 foot negative margin on the Empty setpoint in order to assure the required injection /
recirculation volume above the top of the ECCS discharge header.
The RWS7 r..ust be sampled prior to accepting makeup water from the CVCS tc ensure the proper final boron concentration in the tank.
i Rev. 7 6.3-5c 9/81 l
SNUPPS for use in testing operaLility.
Additional information on testing can be found in Section 6.3.4.2.
6.3.2.E Manual Actions No manual actions ara required of the operator for proper operation of the ECCS during the injection mode of operation.
Only limited manual actions are required by the operator to realign the system for tP-
-Id leg recirculation mode of operation, and, after approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, for the hot leg recirculation mode of operation.
These actions are delineated in Table 6.3-8.
Based on the containment pressure-temperature analyses provided in Section 6.2.1, which assume runout flows of all pumps, including the containment spray pumps, which draw from the RWST, switchover of the RHR pumps occurs approximately 13 7 minutes after the accident. l The changeover from the injection mode to recirculation mode is initiated automatically and completed manually by operator action from the main control room.
Protection logic is provided to automatically open the two safety injection system recirculation sump isolation valves when two out of four RWST level channels indicate an RWST level less than a low-low-l level setpoint in conjunction with the initiation of the engineered safeguards actuation signal (SIS).
When the containment sump recirculation valves are fully opened, RHR pump suction from the RWST is auto-matically isolated.
This automatic action aligns the two RHR pumps to take suction froc the containment sump and to deliver water directly to the RCS.
The RHR pumps continue to operate during this changeover from injection mode to recirculation mode.
The two charging pumps and the two safety injec.isn pumps con-tinue to take suction from the RWST, following the above automatic action, until manual operator action is taken to align these pumps in series with the RHR pumps.
The RWST level protection logic consists of four level channels with each level channel assigned to a separate process control protection set.
Four RWST transmitters provide level signals to corresponding normally de-energized level channel bistables.
Each level channel bistable would be energized on receipt of an RWST level signal less than the low-low-l level setpoint.
A two-out-of-four coincident logic is utilized in both protection cabinets, A and B, to ensure a trip signal in the event that t o-out-of-four level channel bistables are energized.
This trip I
signal, in conjunction with the SIS, provides the actuation signal to automatically open the corresponding containment sump isolation valves.
The low-low-l RWST level signal is also alarmed to inform the operator to initiate the manual action required to realign the
(
charging and safety injection pumps for the recirculation mode.
6.3 19-.
SNUPPS The manual switchover sequence that must be performed by the operator is delineated in Table 6.3-0.
Following the automatic and manual switchover sequence, the two RHR pumps take suction frcm the containment sump and deliver borated water directly to the RCS cold legs.
A portion of the number 1 RHR pump discharge flow is used to supply the two centrifugal charging pumps, which also deliver water directly to the RCS cold legs.
A portion of j
the discharge flow from the number 2 RHR pump is used to provide suction to the two safety injection punps, which also deliver directly to the RCS cold legs.
As part of the manual switchover procedure (see Table 6.3-8, Step 4), the suctions of the safety injection and centrifugal charging pumps are cross connected so that one RHR pump can deliver flow to the RCS and both safety injection and centrifugal chargir.g pumps, in the event of the failure of the second RHR pump.
See Section 7.5 for process information available to the operator in the control room following an accident.
The consequences of the operator failing to act altogether will be loss of the high head safety injection pumps and centrifugal charging pumps.
6.3.3 SAFETY EVALUATION Safety evaluations are numbtred to correspond to the safety design bases in Section 6.3.1.1.
SAFETY EVALUATION ONE - Except for the RWST, the ECCS is located in the reactor and auxiliary buildings.
These buildings are designed to withstand the effectn of earthquakes, tornadoes, hurricanes, floods, external missiles, and other appropriate natural phenomena.
Sections 3.3, 3.4, 3.5, 3.7(B), and 3.8 provide the bases for the adequacy of the structural design of these buildings.
l l
The events which could result in the loss of function of the RWST (i.e., tornado missile) will not also cause a DBA.
Since the BIT is available to provide a borated source of water to achieve and maintain the plant in a safe shutdown, no protection of the RWST is required.
SAFETY EVALUATION TWO - The ECCS is designed to remain functional after an SSE.
Sections 3.7(B).2, 3.9(B), and 3.9(N) provide the design louding conditions that were considered.
Sec tions 3.5, 3.6, and 9.5.1 and Appendix 3B provide the hazards analyses to assure that a safe shutdown, as outlined in Section 7.4, can be achieved and maintained.
6.3-20 l
SNUPPS TABLE 6.3-1 (Sheet 2)
Discharg head at shutoff, ft 3,545 25 Eequired NPSH 44 Available NPSE ASME III, Class 2 Design code Seismic design Category I Driver:
F'ectric motor Type 450 Horsepower, hp 3,600 Rpm 4,160 V, 60 Hz, Power 3-phase, Class IE Start time 55 sec NEMA Derign code Seismic design Category I Residual Heat Removal Pumps 2
Number 600 Design pressure, psig Design temperature, F 400 3,800 Design flow, gpm 350 Design head, ft NPSH required at 4,800 gpm, ft 21 Available NPSH at 4,800 gpm, ft 22.2 ASME III, Class 2 Design code Cate Ucy I Seismic design Driver:
Electric motor Type 500 Horsepower, hp 1,800 Rpm 4,160 V, 60 Hz, Power 3-phase, Class IE Start time SS sec NEMA Design code Seismic design Category I Residual Heat Exchangers (See section 5.4.7 for design parameters)
Refueling Water Storage Tank 1
Quantity Maximum volume 433,000 Normal usable capacity, gal 407,000 l
Minimum usable capacity, gal 378,900 Boric aci'; concentration, ppm boron inominal) 2,000 Vertical, field Type erected i
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SNUPPS TABLE 6.3-8 SEQUENCE OF CHANGEOVER OPERATION FROM INJECTION TO RECIRCULATION i
The operator initiates component cooling water to the RHR heat exchangers and terminates cooling water to the fuel pool cooling heat exchangers as the level in the RWST nears the low-low-l level setpoint.
Without being stopped, the RHR pumps are realigned for the recirculation mode by the automatic opening of the sump isolation valves, which occurt upon re_eipt of the RWST low-low-l level signal and an SIS.
The isolation valve in each RHR suction line from the RWST is then automatically closed.
The follewing remote manual operator actions from the control room are required to complete the changeover operation from the injection mode to the recirculation mode.
1.
Close the two remote motor-operated valves in the crossover line downstream of the residual heat removal heat exchangers (8716 A and B).
2.
Close the three motor-operated isolation valves in the safety injection pump miniflow lines (8814 A and B; 8813).
3.
Open the motor-operated valve in the line from the number 2 RHR pump discharge to the charging pump suction and the motor-operated valve in the line from the number 2 RHR pump discharge to tne safety injection pump suction (8804 A and B).
4.
Open the two parallel motor-operated valves in the common suction line between the charging pump suction and the safety injection pump suction (8807 A and E).
l 5.
Close the two parallel motor-operated valves in the line l
from the RWST to the crarging pump suction and the valves in l
the line from the RWST to the safety injection pump suction l
(LCV 112 D and E; 8806 A and B).
l l
t l
i
SNUPPS
}v TABLE 6.3-11 RWST OUTFLOW (LARGE BREAK) - NO FAILURES l
Time Required ( }( }
RWST Outflow (2)(6)
Change in RWST Volume Total RWST Volume Step {y)
Per Step (sec)
Per Step (gpm)
Per Step (gal)
Change (gal)
RHR Pump I4) ti,3soI7) 19,38o 19,3 %o Switchover 60 1
45 9,Z5 o 6,950 26,330 2
40 9,zso 4,37*
32,n..
J 3
40 9,2.5o 6 s 7o 38,47o 4
40 9,15o fe,170 4 4, f 40 5(8) 40 9,25 o 6, I r e Si,oto (e.58 min 7,45o 49,990 100,000 CS pump switchover 105 7,45o 13, os c.
II3,c5o RWST empty NA NA NA 115,650 NOTES:
(1)
See Table 6.3-8 for a description of the steps 1 through 5.
See Table 6.2.2-3 for a descrip-tion of containment spray pump ovitchover.
(2)
Flow rates are based on runout flows which are conservatively high:
RHR pump
= 4,500 gpm per pump B
CCHG pump =
450 gpm per pump SI pump 450 gpm per pump
=
q CS pump
= 3,12.5 gpm I 'r pump Rev. 7 9/81
6' SNUPPS 1V TABLE 6.3-11 (Sheet 2)
RWST OUTFLOW (LARGE BREAK) - NO FAILURES NOTES:
(Continued)
(3)
Valve operating times are maximum operating times.
(4)
Includes an extra allowance of time (30 seconds) for valves 8811 A/B to automatically open and valves 8812 A/B to automatically close.
(5)
Time required to complete the required action includes a conservative 30 seconds for operator response time for each manual procedure.
The flow rate in this column is ' ssumed to occur during the entire time interval for its respec-(6) a tive step.
This is conservative, since valve repositioning may reduce the flow rate during the time interval.
(7)
Flow out of the RWST during switchover includes allowances for both pumped flow to the RCBS and containment and backflow to the containment sump.
(8)
Following the completion of this step, all ECCS pumps are aligned with suction flow from the con-tainment sump.
The containment spray pumps continue to take suction from the RWST until the RWST low-low level alarm informs the operator to initiate switchover of the containment spray system.
Rev. 7 9/81
SNUPPS
'F TABLE 6.3-12 I9)
RWST OUTFLOW (LARGE BREAK) - WORST SINGLE FAILURE f
I II }
RJST Outflow ( )(6)
Time Required Change in RWST Volume Total RWST Volume U}
Step Per Step (sec)
Per Step (gpm) per Step (gal)
Change (gal) t kHR Pump I4I Switchover 60 19,390 I7) 19,390 19,340 1
45 14,385 10,75o 3 0, f 3.
2 40 14,3 5 9,550 39,(eS o 3
40 14, 315 9,55o 49, 2.3o
]
4 40 14,315 9,550 58,790 5(8) 40 14,3 15 9,55o 6 7,33o CS pump switchover 105 12,680 n,Ito 10,2.5o 8
RWST empty NA NA NA 115,650 NOTES:
(1)
See Table 6.3-8 for a description of the steps 1 through 5.
See Table 6.2.2-3 for a descrip-tion of containment spray pump switchover.
(2)
Flow rates are based on runout flows which are conservatively high:
RER pump
4,500 gpm per pump CCHG pump
450 gpm per pump SI pump 450 gpm per pump
=
CS pump
= 3,725 gpm per pump N
^
sev. 7 9/81
i SNUPPS TABLE 6.3-12 (Sheet 2) 7 NOTES:
(Continued)
(3)
Valve operating times are maximum operating times.
(4)
Includes an extra allowance of time (30 seconds) for valves 8811 A/B to automatically open and valves 8812 A/B to automatically close.
(5)
Time required to complete the required action includes a conservative 30 seconds for operator response time for each manual procedure.
(6)
The flow rate in this column is assumed to occur during the entire time interval for its respec-i tive step.
This is conservative, since valve repositioning may reduce the flow rate during the time interval, 1
(7)
Flow out of the RWST during switchover includes allowances for both pumped flow to the RCBS and containment and backflow to the containment sump.
(8)
Following t';e completion of this step, all ECCS pumps are aligned with suction flow from the con-tainment sump with the exception of one residual heat removal pump due to the single failure.
(9)
Based on a large break LOCA in conjection with a single failure of one of the RWST to residual heat removal pump isolation valves (8812 A or 8812 B fails to close on demand).
i I
J 4
N 4
E+
-f l
Rev. 7 9/81
D i
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E L. 2043'-n 1" RWST LO ALARM 5-------------------.
> 250,000 GALLONS INJECTION WATER FOR ECCS & CTMT
__ SPR AY RWST LO LO-1 g-RHR PUMP AUTO SWITCHOVER l
E. 2006*-7" l> 115.650 GALLONS TRANSFER ALLOWANCE
- - RWST LO LO-2 FOR SCCS & CTMT SPRAY CTMT SPRAY SWITCHOVER ALARM E L. 2004'.11' RWST EMPTY ALARM L 13,520 GALLONS -INSTRUMENTATION ALLOWANCE E L. 2003'-6" TDA OF PlFE 28,130 GALLONS
- - BG(TOM OF P:PE EL 2001'-6" E L. 2000'-6~
(. - - -RWST HEADER : 4400 GALLONS NOTE: TANK VOLUME IS 9380 GAUFT.
SNUPPS FIGURE 6.3-7 RWST LEVELS AND VOLUMES
. -.